For much of the 80's-90's & even early 2000's the automakers (especially the US car companies) put their billions in R&D money into developing SUV's and how to make them bigger and more powerful with more options because that's where the profits were. MPG's were fairly low on the average consumer's radar screen. Back in the 90's when the Explorer was the biggest selling vehicle in the country for the US car companies SUV's & pickups made up about 50% of sales but 90% of their profits. So that's where their investment went.

Had they been putting their money into making cars better AND more effecient today we would have cars that get more MPG's.

In 2024 mabye we don't actually average 54 MPG but even if we can average 45 and have decent sports cars thats a win for everybody. Its not out of the realm of possibility if thats where we focus our efforts.